Problem: Simplify the following expression: ${-(-3x-7)+2(3-12x)}$
Explanation: The minus sign in front of the parentheses means we multiply each term inside the first parentheses by ${-1}$ $ {-1(}\gray{-3x-7}{)} + 2(3-12x) $ $ {3x+7} + 2(3-12x) $ Distribute the ${2}$ into the parentheses: $ 3x+7 + {2(}\gray{3-12x}{)} $ $ 3x+7 + {6-24x} $ Rewrite the expression to group the ${x}$ terms and numeric terms: $ {3x - 24x} + {7 + 6}$ Combine the ${x}$ terms: $ {-21x} + {7 + 6}$ Combine the numeric terms: $ {-21x} + {13}$ The simplified expression is $-21x+13$